Using Pesticide Use Data to Evaluate IPM Programs

Using Pesticide Use Data to Evaluate IPM Programs
Larry Wilhoit
California Department of Pesticide Regulation
Abstract :
A few countries and US states collect data on pesticide use. The most complete and detailed database for production agriculture is the Pesticide Use Reporting (PUR) system in California. These data can be used, at least partially, to evaluate IPM programs, not so much to determine how many growers are using IPM, but to determine whether the goals of reduced risk have been met. However, the use data must be supplemented with other information such as economics, pest levels, weather, human exposure, environmental monitoring, use of other non-chemical pest management practices, and the reasons growers have for adopting particular practices.
We have analyzed pesticide use in California, dividing pesticides into high risk, low risk, adjuvants, and others. Pesticides are considered high risk if they appear on at least one of several lists: organophosphates (OPs), carbamates, California’s Proposition 65 list of chemicals “known to cause reproductive toxicity”, U.S. EPA’s list of B2 carcinogens or California’s Proposition 65 list of chemicals “known to cause cancer”, California Department of Pesticide Regulation’s (DPR) groundwater protection list, or DPR’s toxic air contaminants list. Pesticides are considered low risk if they are on U.S. EPA’s list of reduced-risk pesticides or if they are considered a biopesticide, which include microorganisms and naturally occurring compounds.
Production agricultural pesticide use in California over the period from 1992 to 2001 has not changed much overall. However, use of most pesticides decreased from 1998 to 2001, especially use of high-risk pesticides, while low risk pesticide use has increased. There is not much evidence that this decrease was due to efforts of IPM programs. The primary reasons for these changes seem to be pest pressures and economics.
Of the major crops, the largest decrease in high-risk pesticides has been on cotton. Although apples, pears, and almond have been mentioned as important examples of adoption of low risk IPM programs, there has been only a small reduction in high-risk pesticides and small increase in low risk pesticides. There has been a dramatic decrease in dormant OP use on almonds possibly due to the strong efforts of many organizations concerned about the presence of OPs in surface waters. The low risk alternatives to dormant OPs appear to be effective and are being adopted by many growers. The main low risk alternative is not Bacillus thuringiensis or dormant oil, but no dormant insecticide at all.